Cate Blanchett worried her husband would die before his 40th birthday.

The 'Blue Jasmine' actress admits losing her father at a young age to a heart attack left her paranoid that her partner Andrew Upton - with whom she has sons Dashiell, 11, Roman, nine and five-year-old Ignatius - would succumb to the same fate.

Cate recalled to The Observer magazine: "I lost my father young. The earliest memory I have is seeing him in bed when I was 18 months old - I later learned he was recuperating from his first heart attack at 32. He died when he was 40 [of a heart attack], but I don't think I really quantified the consequences for me until much later, when my husband reached 40.

"I was euphoric at his birthday party, like a weight had been lifted. And I thought, 'Now, there's the detritus'."

The screen beauty realised she had a pessimistic nature when her first reaction upon winning an Oscar for Best Supporting Actress in Martin Scorsese's 'The Aviator' in 2005 was to panic that her career had peaked.

Cate, 44, said: "I can be a real pessimist. You know that when you win an Oscar and you walk offstage and your first thought is, 'Oh God, I've peaked!"

The Australian actress says she gets bored of the sound of her own voice and is looking forward to spending some quiet time with her family next year.

She explained: "My husband and I have been running the Sydney Theatre Company and it's been magic - my kids have been able to see so many of those transient moments between acting and real life behind the scenes.

"But now that I've given it up I'm looking forward to being a bit quieter. I'm very conscious of that. There have been times when I've heard myself in the past and thought, 'Aw, just shut up.' "